FIG. 1 is a perspective view illustrating a discharge cell of a general AC plasma display panel arranged in matrix shape.
As shown in FIG. 1, a conventional PDP comprises a front substrate 10 and rear substrate 12. A pair of sustain electrode 14, 16, upper dielectric layer 18 and protective layer 20 are gradually formed on the front substrate 10, and address electrodes 22, lower dielectric layer 24 and barrier ribs 26 and phosphor layer 28 are gradually formed on the rear substrate 12. The front substrate 10 and the rear substrate 12 are spaced in parallel to each other at a predetermined distance by barrier ribs 26.
Wall charges occurred upon the plasma discharge is accumulated on the upper dielectric layer 18 and the lower dielectric layer 24. The protection layer 20 serves to prevent damage of the upper dielectric layer 18 due to sputtering generated upon the plasma discharge and to increase emission efficiency of secondary electrons. The protection layer 20 is usually formed using magnesium oxide (MgO).
The address electrodes 22 are formed in the direction intersecting a pair of sustain electrodes 14, 16. A data signal is supplied for the address electrodes 22 to select a cell that is displayed.
The barrier ribs 26 are formed in parallel to the address electrode 22 and serves to prevent ultraviolet rays and a visible ray generated due to the discharge from leaking toward neighboring discharge cells. The barrier ribs 26 may be existed or not a boundary line of sub-pixel.
The phosphor layer 28 is excited by ultraviolet rays generated upon the plasma discharge to generate a visible ray of one of red, green and blue. Inert mixed gases such as He+Xe, Ne+Xe and He+Ne+Xe for discharge are inserted into a discharge space of the discharge cell formed between the upper/lower substrates 10, 12.
A pair of sustain electrode 14, 16 comprises scan electrodes 14 and sustain electrodes 16. A scan signal for scanning of the panel is supplied for scan electrodes 14 and a sustain signal for maintaining discharge of a selected cell is supplied for sustain electrodes.
A pair of sustain electrode 14, 16 comprises transparent ITO electrodes 14A, 16A, which are stripe pattern, are made of transparent material in order to transmit a visible ray and have a wide width relatively, and metal electrodes 14B, 16B, which compensate a resistance of transparent ITO electrodes 14A, 16A and have a narrow width relatively. Each of the transparent ITO electrodes of a pair of sustain electrodes 14, 16 is opposite to each other at a predetermined distance. Further, metal electrodes 14B, 16B are formed in parallel to the transparent ITO electrodes 14A, 16A and formed on a verge of the transparent ITO electrodes 14A, 16A, respectively. Namely, metal electrodes 14B, 16B are formed on outside verge of the transparent ITO electrodes 14A, 16A.
A PDP cell of this structure sustains a discharge according to surface discharge between a pair of sustain electrodes 14, 16 after being selected by opposite discharge between the address electrode 22 and the scan electrode 14. In the PDP cell, a visible ray is emitted to an outside of cell as radiating phosphors 28 by ultraviolet rays which are generated while the sustain discharge occurs. As a result, the PDP having cells displays an image. In this case, the PDP realizes a gray scale by controlling the discharge sustaining period, i.e. the number of sustain discharge according to a video data.
In the conventional PDP, Xe inert gas excites phosphors 28 using a vacuum ultraviolet generated by changing from excited state to ground state according to gas discharge. Therefore, as a content of Xe is much, a quantity of vacuum ultraviolet rays generated upon the gas discharge and the efficiency of the PDP increase. However, the increase of Xe is caused by rising discharge starting voltage and discharge sustaining voltage between sustain electrodes.
Furthermore, in the conventional PDP, the discharge starting voltage and the discharge sustaining voltage is raised because the metal electrodes 14B, 16B are formed on the outside verge of the transparent ITO electrodes 14A, 16A, respectively. Also, the brightness and efficiency of the conventional PDP are decreased.
That is, the conventional PDP structure has a difficulty in increasing brightness and efficiency without any problem such as the structure of electrodes within the discharge cell.